How do you deal with this fungus on tomatoes leaves?

Hi,

After killing at least 6 (maybe it was 8) cherry tomato plants, I finally have this gorgeous baby who is blooming and fruiting despite a little heat stress. (Its a different variety of tomatoes -not cherry- I have never grown before and seems like a determinate one).

Only, this time there is a new problem with the leaves. These dried spots appear as circles on the leaf surface as well as the edges in you notice in the pictures. I thought it was a fungus and tried spraying the plant with vinegar & baking soda in water solution.

I also realized it affects the part of the plant that is a little shaded. Have had to remove a lot of leaves because of this.

Is there anything I'm doing wrong? What can I do to save it from further damage?

The weather is strange this year, we are in the middle of December and humidity is quite high at this time, it's gets quite hot during the day sometimes and we sweat despite the cold (the tomato flowers also show a clear sign of heat stress) yet the sun doesn't shine evenly and regularly.

Maybe there are mites, probably not but a possibility. You can maybe check for them and use organic control like neem or pyrethrin.

You said it affect the shaded parts, I would give the plant more sun exposure maybe, tomatoes hates humidity, it is a desert plant after all.

This message was edited Dec 16, 2014 11:20 AM

I suspect the trouble is a Mould, Most Tomato plants are prone the this, humidity is a cause, watering or misting the foliage can cause and spread the mould, as can any insects the fly or crawl from plant to plant.
There is also a disease called Tomato Blight, looks much the same as the mould BUT this also affects the actual tomato's, In my Greenhouse (I need to grow my tomato's inside here in UK) as soon as I find Blight, I cut the plants down and burn them or it can spread very fast to other plants like Peppers and Cucumbers etc,
I suspect your plant needs less water near the foliage and a little more bright light from the sun in day time. I find these diseases are less trouble when I water my plants from below and nor gwt wet onto the foliage, also when you see the first few leaves being attact, it's a good idea to remove the damaged leaves and burn them, wash your hands and any cutting tools or soil tools used also as you can spread it without realising the mould / blight is on your hands and tools.
Hope this helps you out a little.
Kindest Regards.
WeeNel.

Hi maxjhonson, there were spider mites in the basil nearby (I shot them with lots of citrus infused vinegar spray which seemed to have helped the basil) but they don't enter the tomatoes as far as I've observed. It is the lower leaves that get affected and looks a lot like blight or fungus. I'm just unable to use any spray on the foilage as humidity is very high and there is little sunlight in the spot where they are growing nowadays. Do you think spraying dry baking soda on the foilage could help or is it harmful?

Weenel, Thank you. Silly I didn't think of this earlier but I'll start watering them from below too. I'm going to have to destroy a lot of leaves today as more foliage has been affected and I can see one tomato developing signs of blossom end rot too.

vanita, there is every possibility that where you remove diseased or damaged leaves, withing a week, you will find new leaf buds forming on the stems, just make sure you have removed the damaged leaf right back to the stems as there could be Mould or Blight hidding in the leaf axle where the leaf meets the stem.

If I were you, I would MIST the top soil very slightly as this might help prevent the spores of mould etc being blown upwards.
Dont overdo this misting by soaking the soil, I'm thinking JUST the very top of the pot, enough to just allow the smell of the Vinegar to keep any bugs / mould etc away OR use an eggcup of vinegar set beside the pot or between them to help.

As for Mites, I would remove any plants to the outside as soon as you see mites, these tiny little bugs are invisible till you see their damage and usually by then the plants are way beyond saving AND the mites can travel and spread very quickly from plant to plant, they like soft foliage and the first you know you have them is by noticing the very soft, fine, downy looking webs.
Most mites hate humid conditions so misting underside of the leaves are a way to prevent the mites breeding but it wont get rid or kill them.
Hope your Plants pick up and you can get a crop of Tomato's.
Good luck and kind regards.
WeeNel.

Hi Weenel,

Got your msg a little late but most of the leaves are ruined as of now (we had a lot of rain last month and that is what caused maximum damage). The problem is no new leaves really came up from where I removed the old ones. However, I did manage to get a few good tomatoes out of that plant and even saved a few seeds. Thanks anyway, I will try vinegar in a egg cup next time I'm growing this variety. Sounds good.